Drop nozzles are used with row crops where it is necessary to spray the lower portion of the plant with a herbicide or insecticide. A number of individual nozzle assemblies are mounted in a spaced manner along the length of a boom structure attached to an agricultural sprayer vehicle, with the nozzles disposed intermediate adjacent crop rows. Each drop nozzle assembly includes an elongated, vertically oriented tube attached at its upper end to the boom-mounted drop nozzle bracket and having one or more spray nozzles at its lower end. The nozzle assembly tube must be long enough to provide spraying access to a lower portion of the plants, while allowing the boom to pass over the crop rows which may be varying in length from one to several feet depending on the crop. Not only does the height of the crop vary depending on the type of crop, but as the growing season progresses the height of the crop also increases under normal conditions. Moreover, crop row spacing generally varies between different types of crops and even from field to field for the same types of crops.
A drop nozzle assembly is typically mounted to the spraying vehicle's boom by means of a threaded U-clamp, or directly attached to the nozzle bodies on the boom. In case of the U-bolt design, moving the individual nozzle assemblies to accommodate the change in crop row spacing involves loosening two nuts from the clamp, removing the clamp from the boom, and relocating the mounting clamp on the boom. The nozzle assembly cannot simply be slid along the boom following loosening of the U-clamp to a new position on the boom because of the presence of trusses and other structures along the length of the boom. The U-clamps employed are typically of a relatively large size and have extended threaded shafts to accommodate a range of boom sizes and shapes, making nozzle assembly removal time consuming and tedious. In the case where the drop nozzles are attached directly to one of the permanent nozzle holders on the boom, there is not only a need for a large number of nozzle holders to accomodate for different row spacing, but there is also a substantial risk of damaging the permanent nozzle holder if the attached drop nozzle should encounter an obstacle. In the case of a custom sprayer who may operate on a large number of different fields each day, changing the position of the nozzle assemblies along the length of the boom becomes impractical and attaching nozzle assemblies for every possible row crop spacing is economically prohibitive.
The present invention addresses the aforementioned limitations of the prior art by providing a drop nozzle system and a quick disconnect holder mount therefor which employs a plurality of sets of mounting plates attached in a spaced manner along the length of the sprayer boom, where each set of mounting plates is adapted to accommodate a given inter-row crop spacing. The quick disconnect holder mount permits each drop nozzle assembly to be quickly and easily removed from a mounting plate of a first set and attached to a mounting plate of a second set to accommodate a change in crop row spacing. The use of a "jumper hose" further allows the operator to connect the drop nozzle to the closest existing nozzle holder rather then attaching to a special nozzle holder that lines up with the row.